Polarized Optics for Optical Diagnostic Device

Abstract

A readhead for a photometric diagnostic instrument includes a holder configured for receiving reagent sample media therein. The sample media has a plurality of test areas configured to react with, and change color, according to an amount of an analyte in a sample. The holder is sized and shaped for forming an indexed fit with the sample media. One or more light sources are configured to emit light onto the test areas. First and second polarized light filters are respectively disposed between the light sources and the test areas, and between the test areas and one or more light detectors, so that the light detectors receive diffuse, non-specular reflections of the light from the test areas, while substantially preventing the light detectors from receiving specular reflections of the light.

Description

BACKGROUND[0001]1. Technical Field[0002]The present invention generally relates to the field of clinical chemistry. More particularly, the present invention relates to a readhead for an optical diagnostic system that analyzes the color change associated with one or more test areas on sample media following contact thereof with a liquid specimen, such as urine or blood.[0003]2. Background Information[0004]Throughout this application, various patents are referred to by an identifying citation. The disclosures of the patents referenced in this application are hereby incorporated by reference into the present disclosure.[0005]Sample media such as reagent test strips are widely used in the field of clinical chemistry. A test strip usually has one or more test areas spaced along the length thereof, with each test area being capable of undergoing a color change in response to contact with a liquid specimen. The liquid specimen usually contains one or more constituents or properties of inte...

AI Technical Summary

Benefits of technology

[0012]An aspect of the present invention includes a readhead for a photometric diagnostic instrument, for illuminating a target area and detecting color information from the target area. The readhead includes a holder configured for receiving reagent sample media therein, the sample media having a plurality of test areas disposed in spaced relation thereon, each of the test areas configured to react with a sample when disposed in contact with the sample and to change color according to an amount of an analyte in the sample. One or more light sources are configured to emit light onto the test areas. One or more first polarized light filters having a first polarization direction are disposed optically between the light sources and the test areas, so that light reaching the test areas from the light sources is polarized in the first polarization direction. One or more light detectors are disposed to receive light reflected from the test areas. One or more second polarized light filters having a second polarization direction are disposed optically between the test areas and the light detectors. The first and second light filters are configured to enable said light detectors to receive diffuse, non-specular reflections of the light from the test areas when the sample media is indexed within said holder. The first and second light filters are also configured to substantially prevent said light detectors from receiving specular reflections of the light.

Problems solved by technology

Color comparisons made with the naked eye can lead to imprecise measurement.

A drawback of using this relatively large field of view, is that there is also a relatively great degree of opportunity for specular reflections from the light source to enter the field of view and obscure the image of the pad.

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